Armored vehicles are threatened by improvised explosive devices (IEDs) designed to cause harm to the vehicle and its occupants. IEDs are typically one or more grouped artillery shells redeployed and detonated in an effort to inflict casualties. These explosive devices when detonated beneath a floor of a vehicle, these explosive devices often create localized deformation of the floor of the vehicle thereby transmitting large vertical loads onto the lower extremities of occupants of the vehicle. For example, detonations below the underbelly of an armored vehicle may cause the vehicle floor to accelerate at 100G or more and reach velocities of 7 to 12 m/s over a time period of 3 to 5 msec. These high rates of acceleration and velocity transmit large mechanical forces on the lower extremities of the occupants within the vehicle cabin.
Armor countermeasures typically consist of heavy metal plates placed between the threat and the vehicle in such a way as to resist hull breach and aggressive floor accelerations. These heavy metal plates also work in concert with layers of additional metal, ceramic, composite or plastic materials designed to prevent lethal high velocity artillery shell fragments from entering the vehicle. The heavy metal plates are typically mounted to the underside of the vehicle in a V-shape in an effort to take advantage of shape efficiency and deflection characteristics when presented with incoming pressure and fragmentation. Carrying a heavy blast and fragment resistant hulls results in significant performance disadvantage to the vehicle in terms of reduced fuel economy, lost cargo capacity and increased transportation shipping costs.
The present device usable, for example, in a personnel cabin of a vehicle, includes a two stage dissipating system for dissipating the blast forces from an explosive device. The device includes an absorbent mat, a suspended floor, and an air bag, which is deflated through use of a blast sensing apparatus. The absorbent mat, air bag and suspended floor help improve the dissipation of forces exerted on the underbelly of the vehicle while avoiding the negative tradeoffs of alternative designs.